(1) Field of the Invention
This invention relates to motorcycles, and more particularly to telescopic motorcycle forks and to reservoirs for height-adjustable motorcycle shock absorbers.
(2) Description of the Related Art
The dominant class of front suspension for motorcycles is the telescopic fork. Each of a left blade and a right blade of the fork includes telescoping members which extend and compress responsive to loads between the motorcycle frame and the front wheel. Each blade includes one or more springs which provide the necessary static compression resistance and hydraulic valving components which provide damping (shock absorption). Many telescoping forks have a height adjustment feature allowing adjustment of the static blade extension for a given static load. Although the art is extremely developed, there remains room for various combinations of enhanced performance and simplified manufacture.
Many shock absorbers (rear or front) include external reservoirs which receive hydraulic fluid from the shock absorber as it is compressed and return such fluid to the shock absorber as it is extended. The reservoirs may be gas-pressurized (such as by introduction of air). When air is introduced to the reservoir, it will tend to drive some of the hydraulic fluid back into the shock absorber thereby extending the shock absorber and increasing static ride height. Withdrawal of air similarly lowers ride height.
Valving of the fluid flow between the reservoir and shock absorber will affect the shock absorption characteristics. A user-adjustable valve or valves may be provided. The size of the reservoir, along with desired access for air introduction and valve adjustment are among factors which render reservoirs difficult to conceal so as to reduce visual clutter.
Although there is a well developed art in shock absorber reservoirs, there remains room to provide a reservoir having various combinations of improved performance, simplified manufacture, and aesthetic appeal.
In one aspect, the invention is directed to a motorcycle fork blade including a leg for engaging a front wheel axle, a lower tube extending upward from the leg and an upper tube telescopically surrounding the lower tube. An upper endplug extension with an upper end portion of the upper tube. An elongate member depends from the endplug. A spring is longitudinally captured between the leg and a fixture on the elongate member so that the fixture and spring are maintained within the lower tube during a normal range of travel of the blade so as to minimize possibility for binding of or damage to the spring.
In another aspect the invention is directed a height adjuster featuring a threaded stud accommodated within a bore of a stanchion tube endplug and carrying a fixture for engaging a main spring of the blade.
In another aspect the invention is directed to a shock absorber reservoir assembly.
In another aspect the invention is directed to use of a gas-filled bladder on the extension side of a shock absorber to provide volume compensation.